Vacuum devices having vacuum-sealed vacuum containers such as electron tubes, CRTs, and the like have conventionally been known. An example of such vacuum devices is an image display apparatus described in the following Patent Document 1. This image display apparatus has a vacuum container in which a front faceplate and a back faceplate are joined to each other by a seal material.
Patent Document 1: Japanese Patent Application Laid-Open No. 2002-352713